The item hasn't arrived yet, and will probably arrive in week and a half or so, it's from China... but for when it does get here, is there a guide on how to replace the cover? I am fairly certain iFixit is overcomplicating it.. Can't you use a suction cup or tools?

Is someone able to give me some wisdom on how to actually perform the repair in the most sane way?

I haven't done it myself nor do I have a n3ds. But I'd guess it's like the original 3ds and 3ds xl and is just stuck on there with glue. If that's the case you'll probably do fine with a suction cup and the plastic tools in the picture. I'd recommend using a hair dryer as well to heat up the glue which will make it unstick a bit.

I'd have to remove it before they have a look at it! With the possibility of me then restoring my NAND backups to a (possibly) refurbished unit, the risk isn't worth it... It seems astronomically easier to just replace the glass myself.